1. Field of the Invention
The present invention concerns a test assembly and a procedure for capturing measurement data with a sensor unit, the sensor element of which supplies measurement signals and an analysis unit connected with it by a measurement line that transforms the measurement signals into measurement data, whereby in or on the sensor unit a sensor identification is provided that can be polled by the analysis unit, and with a storage unit in which the first set of sensor-specific data that is allocated by the polled sensor identification are stored that can be read by the analysis unit.
2. The Prior Art
In test assemblies, particularly in test stand environments, such as, for example, a test for combustion motors or drive trains or entire vehicles, a number of sensors are used in order to capture various measurement variables such as, for example pressure, temperature, etc., analyze such and process such further. The individual sensors, even those of the same type and model are thereby individual units with various parameters and calibration data such as, for example ranges of measurement, sensitivities, operating times, etc. Moreover, additional data are also connected with sensors, such as, for example, serial numbers, manufacturers, useful life, etc. An analysis unit that must process the data supplied by the sensors must, in order to deliver correct measurement results, consider the sensor-specific data and must therefore be supplied with this data or calibrated. Such a calibration process is, however, particularly in an environment with many sensors, an expensive and error-prone process. For this reason, a number of improvements have already been proposed, at least to make an automatic calibration of the analysis unit possible with the sensor-specific data.
From EP 1 302 755 B1 and U.S. Pat. No. 5,792,951 A it is known to locate a data carrier with sensor-specific data such as, for example, calibration data at a distance from the sensor element in a plug for connecting a cable for the purpose of connecting the sensor with the analysis unit. In order to ensure a clear and safe allocation of the stored sensor-specific data to the sensor, the plug must be inseparably connected with the sensor element—the sensor element with the connection cable and the plug thus forms an inseparable unit. If a sensor must be exchanged, the entire unit must consequently be exchanged, which in turn increases costs, as the cable and the plug normally are not damaged in operation and could consequently be used again. Moreover, there is no guarantee that the data carrier in the allocated plug also actually pertains to the inseparably connected sensor, as even in a firm connection of the plug with the sensor a mix-up could take place that can subsequently not be determined easily.
EP 1 300 657 A2 in turn describes an arrangement in which in or on the sensor element an identification unit with sensor identification is located with which the sensor unit can be identified. The sensor identification can be read by the analysis unit and can be used for polling sensor-specific data from a storage unit that is at a distance from the sensor unit. With that, a clear recognition of the sensor unit and the allocation to the sensor-specific data that was stored for the sensor is guaranteed. However, this allocation requires that the sensor-specific data is actually stored in the storage unit and is also correctly allocated to certain sensor identification. On the one hand, this increases the administrative effort as the storage unit must always be kept up to date. On the other hand, the problem of errors is thereby only displaced from the cabling to the allocation of the sensor identification of the sensor-specific data in the analysis unit or storage unit.
An error recognition, for example, in cabling, in the stored data or in the data allocation is, however, not possible in either process. Thus, in both variants, a certain residual risk of error remains which could end up as a (non recognizable) erroneous measurement.
It is therefore an objective of the present invention to indicate a process and an arrangement for capturing measurement data with automatic calibration by an analysis unit that also makes error recognition in the calibration or in the allocation of a sensor to sensor-specific data possible.